The present invention relates to novel devices for applying a lubricating medium to the skin and, more particularly, to disposable razor blade cartridges including such devices.
Various personal care products for imparting lubricity to the skin or hair are well known in the art.
While not intended to be exhaustive of the state of the art, the following patents may nevertheless be taken as exemplary.
U.S. Pat. No. 4,128,631 relates to pre-electric shave skin conditioners and the like containing polymers of 2-acrylamido-2-methylpropane sulfonate to lubricate keratinous substrates such as skin and hair.
U.S. Pat. No. 4,585,650 issued to Newberry et al discloses water-based compositions for lubricating the skin for shaving, which compositions are thin lotions including a mixture of effective amounts of water, a gel former and binding agent, a gelling agent with skin conditioning properties and an emollient.
Of particular interest for a clear understanding of the nature and primary objectives of the present invention, reference is made to U.S. Pat. No. 4,170,821 issued to Booth which relates to a solid water-soluble shaving aid incorporated in a disposable razor blade cartridge. As is disclosed therein, the shaving aid, which will gradually dissolve during the act of wet shaving, is in the form of a lubricant, whisker softener, razor cleaner, medicinal agent, cosmetic agent or combination of the above embedded, dispersed into, formed as an integral component of, or otherwise affixed to the razor blade cartridge structure adjacent the shaving edge or edges of single or multiple razor blades supported therein.
As is discussed in Col. 1 of the Booth patent, in wet-shaving razor systems, there can be experienced a degree of uncomfortableness due to frictional drag of the razor across the skin, the force needed to sever and the mechanical strength of the hair protein structure, clogging of the razor parts with whisker and skin debris and/or the uncomfortableness of shaving nicks and cuts, irritation or pre-existing skin damage or eruptions and uncontrolled bleeding. According to the patentee, various attempts to remedy at least some of these drawbacks have included the use of pre-shave and after-shave lotions, special whisker softening lathers, blood coagulants and other medicinal agents or soothing creams. While shaving comfort can be enhanced, at least to some extent, with one or more of these aids, the requirement that they be applied before and/or after shaving with evaporation or repeated shaving strokes lessening the effectiveness of pre-applied aids and post-shaving application serving only as after-the fact treatment, much is left to be desired in matters of improving shaving comfort.
Accordingly, the patented invention is directed to the task of improving wet shaving, which task is solved by providing for the application of a shaving aid directly to the skin continuously with each stroke of the razor, the shaving aid being a simple inexpensive integral part of a disposable razor blade cartridge which, itself, is disposable along with the cartridge when one or both are spent.
Various embodiments of the shaving aid component of the disposable razor blade cartridge are described and shown in the drawings. In the embodiment of FIG. 1, it is in the form of a strip cemented to the cartridge cap, preferably within a recess provided therefor. The shaving aid strip is disposed in juxtaposition with the blade edges and extended from a point adjacent to one end of the blade to a point similarly adjacent to the opposite end of the blade.
As is stated in the paragraph bridging Cols. 2-3 of the patent, the shaving aid strip may comprise one or more of the following: (a) a lubricating agent for reducing frictional forces; (b) an agent which reduces the drag between the razor parts and the shaver's face; (c) an agent which modifies the chemical structure of the hair so that the blade passes through the whiskers very easily; (d) a cleaning agent allowing the razor parts to be washed more easily; (e) a medicinal agent for killing bacteria or for repairing skin damage and abrasions; (f) a cosmetic agent for softening, smoothing, conditioning or improving the skin; and/or (g) a blood coagulant.
The present invention is directed to modifications of the teachings of the aforementioned U.S. Pat. No. 4,170,821 of Booth to provide a lubricating device for applying a lubricious substance to the skin during repeated usage, which device finds particular usefulness as a shaving aid component of disposable razor blade cartridges of the type illustrated in the above-mentioned patent to provide certain significant improvements to be detailed hereinafter.